Which expression is not equivalent to the other expressions?

-6 (2x - 4)

- (12x - 6) + 18

-3 (4x - 3) + 15

-4 (3x + 6)

-6 (2x - 4) = - 6 * (2x) - 6 * (-4) = - 12x + 24

- (12x - 6) + 18 = - 12x + 6 + 18 = - 12x + 24

-3 (4x - 3) + 15 = - 3 * (4x) - 3 * (-3) + 15 = - 12x + 9 + 24 = - 12x + 24

-4 (3x + 6) = - 4 * (3x) - 4 * (6) = - 12x - 24

All the expressions gave the same answer as - 12x + 24, except for the last expression.

So, - 4 (3x + 6) is not equivalent to the others.